Optical coherence tomography is one of the most rapidly developing biomedical imaging modalities. In this technique, the structural information is derived from the light backscattered or backreflected at the interfaces between the regions of different optical properties within the object. OCT technique enables two- or three-dimensional cross-sectional imaging with micrometer resolution. Recently, ultrahigh speed and ultrahigh resolution Spectral OCT imaging using CMOS and swept-source OCT has been demonstrated. Imaging speeds of more than 1,000,000 optical A-scans per second has been already achieved. High speed enables reducing motion artifacts and applying a high density sampling. Recent speed achievements in the high speed instrumentation open new perspectives for the further development of optical imaging modalities. The latter is especially important since OCT techniques can reveal and visualize such properties of biological objects as velocity of flow (via Doppler effect), birefringence (via polarization changes) and tissue extinction supplementary to the morphology. In my presentations I will give insight into the basics of OCT imaging modality to show the basic limitations and potential field of development of coherence imaging methods. I will also demonstrate new advancements of ophthalmic OCT instrumentation both in morphological and the functional imaging. I will also show how the speed and the resolution can be converted into a new quality of functional information by an efficient use of the phase and the amplitude of measured signal in Fourier domain systems.